In this developer diary for the PlayStation 3's MAG - Massive Action Game, Zipper Interactive talks about the challenges of creating a first-person shooter in which 256 players can participate all at once.

While this clip does go into some of the technical side of creating a game for 256 simultaneous players at once, the main thing it does is talk about how awesome it is going to be, and how big of a leap the 256 player mark really is. I think we've established that already though, haven't we? Until I am actually in the middle of a firefight with 255 other people around me, the game still remains a pretty yet slightly above average shooter.